Check mechanism



Nov. 12,1940. E DAWS 2,220,995

CHECK MECHANISM Filed July 23, 1937 DFIG.I

FIG. 2

- INVENTOR.

, RNEST DAVIS BY I M/Qf W ATTORNEYS.

passage.

Patented Nov. 12, 1940 L 7-. n t t v t UNITED "STATES PATENT OFFICE.

' Ernest Davis, Syracuse, N. Y., assignor to The Prosperity Company, Inc., Syracuse, Y., a corporation of New York 7 p Application July 23, 1937, Serial No. 155,289 V t J -80laims. (cram-s l I W This invention relates tohydraulic checks 'or This check device comprises, generally, a cas check mechanisms, and has for its object a-che'ck ing formed with a reservoir for a hydraulic liquid mechanism including a valve or valves for conand one or more piston orplunger chambers comtrolling the transfer of hydraulic liquid from one municatin'g with the reservoir, pistons or plung side of the piston or plunger to the other, durers working in said chambers respectively, the ing the movement of the piston or plungen which structure being formed with a transfer passage vaive or valves are separate from the piston or or by-passfrom onesid'eof the piston or plunger, plunger and are-supported by the casing in conor of each piston or plunger, to the other side, tradistinction to being carried by the plunger or valve means for controlling said transfer passage piston, and which are readily adjustable and also or by-pass, carried by thecasing, and being re readily removable from the outside of the casing movable and replaceable from the outsideof the without disturbing the plungers or parts within casing; or valve mechanism removable fromthe the casing. outside of the casing entirely independent of the It further has for its object a check mechanism movable parts, as the pistonsor plungers, and an in the valve which controls the flow of liquid actuator coacting with the piston or plunger or 16 from one side to the otherof the piston and is pistons or plungers; 1 i

floatingly mounted so as to be self-alining. It I designates, generally, the casing formed with also more specifically has for its object a check a portion 2 serving'as anoil reservoir or aresermechanism including a tapered pin or its equivavoir for a hydraulic liquid. 3 and 4 designate'relent, carried by the casing, in contradistinction to spectively piston or plunger chambers communithe piston and entering a passage in the piston, cating with the reservoir. The casing in the ilwhich pin is formed with a check valve controlled lustrated embodiment of my invention is in the passage therethrough and also such pin being general form of'a conduit with a tower 5extend mounted to have a self-aiming movement in the ing upwardly from t the intermediate portion t I thereof, the end portions of the conduit forma- It further has for its object a check mechanism tion constituting the piston chambers 3, 4, and including oppositely movable, or alternately acthe intermediate portion and also the lower portuated, pistons or plungers and a reversely movation of the tower forming the oil' reservoir. The le actuator coacting with the plungers alter piston chambers 3, 4 are thus located in opposite nately by a lost motion, so that there is a lost portions of thecasing and are below the level L motion period, when the actuator is moving retof the hydraulic liquid. These chambers are rogradely away from one plunger toward and into open at their outer ends, and their outer ends are engagement with the other plunger. closed by closures or caps 6, I, hereshown *as It further has for its object a particularly simthreading on the ends'ofthe tubular conduit por 7 pie and economical construction of check mechtions of the casingconfiriing the piston or plunganism and the casing thereof to provide a reserer chambers 3, 4.

Voir for the hydraulic liquid, with the actuator 8 and 9 are the plungers or pistonsor other mounted outside of'the reservoir and the: liquid movable elements, reversely movable in" the and extending into the liquid, so that liability of chambers 3, 4 respectively.

the liquid working its way out of'the casing is ID and H designate transfer passages from one entirely eliminated. end to the other of the pistons or plungers 8, 9, The invention consists in the novel features these transfer passages being preferably, and and in the combinations and constructions herehere shown as, formed entirely in the pistons inafter set forth and claimed. or plungers, and also preferably extending ax- In describing this invention, reference is had ially of the pistons or plungers. These transfer to the accompanying drawing in which like charpassages H], H are here shown as formed with acters designate corresponding'parts in all the branches l2, l3 opening through the opposing views. ends of the pistons'into the reservoir. The trans- Figure 1 is a longitudinal sectional view of a fer passages are controlled by valve means sepa checking mechanism embodying this invention. rate from the pistons or plungers and carried by Figure 2 is a sectional view taken approxithe casing, or removable from the outside of mately on the line of 2-2, Figure 1. the casing. The valve means are carried by the Figure 3 is an enlarged fragmentary sectional removable caps 6, I andeach includes a member, view of one of the members or pins of the check as a pin orrod 14 or I5 threading through the mechanism. l

cap 6 or 1 from the outer side thereof and extending into the passage ID or I I. It is formed of such shape, as for instance, tapered, so as to progressively close the passage or II, and hence progressively retard the movement of the plunger or piston 8, 9 in one direction, and hence effect uniform progressive checking in accordance with the speed of the piston or plunger. This is in effect a throttling means dependent for its throttling or checking eifect on the speed of the piston; 1

The valve means further includes a check valve, as a spring-pressed ball I6 in a transfer passage or by-pass I! in each of the members M or IE, each passage I! extending through the inner end of each member l4 and having branches l8 opening into the piston or plunger chambers 3, 4 near the heads or caps 6, I. The valve or ball l6 coacts with a seat l9 removably mounted or threading into the member I 4 at the inner end of the passage IT. The member M or I is readily adjusted axially of the pistons or plungers 8, 9 or the caps 6, 1, and is also readily removable for repairing or replacing the check valve l6. Also, the pistons or plungers 8, 9 are readily assembled in the casing and readily removable and replaceable by reason of the caps 6, 1. Thus, the valves or valve means, which are generally the source of trouble in checking devices, are readily accessible without disturbing the internal parts of the, checking mechanism, as the pistons or plungers.

The member M or I5 is here shown as mounted in a passage 20formed in a threaded gland or elongated nut 2| which threads into the cap 1, the pin or member M or I 5 having a head 22 located at the bottom of a countersink 23 opening through the outer end of the nut 2|. A plug 24 threads into the countersink against the head 22. A look nut 25 holds the nut 2| in its axially adjusted position, and hence holds the pin M in its axially adjusted." position. In .order that the pin M or l5 may have a self-alining action relative to the passage ID or I l, the pin is mounted to shift radially, and as here shown, the passage 20 in the nut 2| is of slightly larger diameter than the pin 14 or l5 to provide a clearance around the pin, and the countersink 23 is also of sufliciently large diameter to provide a clearance around the head 22 to permit it to shift radially, and aline the pin I 4 or l5, if its tapered end or tapered side should engage the wall of the passage ID or I l in the piston, during the movement of the piston. A suitable spring or spring washer 26 is interposed between the plug 24 and the head 22.

The actuating mechanism includes areverse- 'ly movable actuator 28, here shown as an arm, suitably mounted on a rock shaft 29 journalled in bearings in the tower 5 outside of the oil in the reservoir or casing, the normal level of which is indicated by the line L'. The actuator arm 28 extends into the reservoir between the opposing ends of the pistons 8, 9 and acts to alternately press against the inner end faces of the pistons or plungers 8, 9. The space between the pistons or plungers 8, 9 is of considerably greater width than the actuator arm, to provide a lost-motion while the actuator arm is traveling retrogradely away from one piston toward and into engagement with the other. The inward or retrograde movement of each piston is limited by shoulders 2 so that either piston can not follow up the actuator arm 28 while it is actuating the other piston, and there is the lost motion referred to between the pistons and the actuator arm. The

actuator arm actuates each plunger or piston 8, 9 in one direction against the action of a returning spring 30 or 3| thrusting at one end against the cap 6 or 1 and at its other end against the piston 8 or 9, the piston 8 or 9 being provided with an annular channel for receiving the spring. The shaft 29 is intended to be connected to some part of the machine or apparatus, which has a back and forth or reverse movement, as for instance, to the movable part of a garment pressing machine in which a head moves toward and from a buck, and for the purpose of connecting the shaft 29 to a. mechanism to be checked in its movement, the shaft 29 is provided with an arm 32 mounted thereon outside of the casing I or the tower 5 thereof,which may be connected to any motion transmitting part, as a link 33. The upper end of the tower 5 is closed by a removable closure 34.

-In operation, after the oil has been filled into the casing or reservoir through the filler hole normally closed by a plug 35, the members I4 or l5 are adjusted independently of each other to produce an equal or differential checking effect. For instance, a machine having an opening and closing movement might require checking movement during closing different from during opening. During the movement of the actuator arm 28 in one direction, as say, to the left (Figure 1), it presses against the piston or plunger 8, moving it to the left into the position shown in Figure 1. During this movement, the oil passes from the left hand side of the piston or plunger 8 through the transfer passage l0 and branches l2 thereof to the inner or left hand side, and the flow thereof is gradually or progressively retarded in accordance with the speed of the piston, due to the taper of the member I. This member l4 may be adjusted axially to adjust the retarding effect to the particular conditions or installation. During this movement of the actuator arm 28, the piston 9 is being moved to the left by its spring 3|, the oil passing its check valve I 6 through the passage l1 and branches I8 thereof. During movement of the actuator arm 28 in the other direction, or to the right, the oil then passes the check valve l6 and through the passage I! and branches [8 thereof, while the piston or plunger 8 is being moved to the right by its spring 23. Due to the lost-motion or spacing between the pistons 8, 9, the actuator arm 28 moves with no checking effect, until the lost-motion is taken up and it presses against the inner head of the piston or plunger 8 or 9, so that at the start of the opening or closing or analogous movement of an apparatus, to'which the checking device is connected, there is no checking effect while static inertia is being overcome.

' What I claim is: s

l. A check mechanism comprising a casing formed with a reservoir and a plunger chamber communicating with the reservoir, a plunger movable in the chamber and having a transfer passage opening throughits opposite ends, means for controlling the flow of liquid through said passage during the movement of the plunger including a member adjustably mounted in the casing and operable from the outside thereof, said member extending into the transfer passage and shaped exteriorly to progressively close the passage through the movement of the plunger as the plunger moves in one direction, and means for actuating the plunger in reverse directions.

2. A check mechanism comprising a casing formed with a reservoir and a piston chamber communicating with the reservoir, a piston movable in the chamber and formed with a transfer passage opening through its opposite ends, valve means separate from the piston for controlling the flow of liquid through the passage during the movement of the piston, said valve means being supported by the casing and operable from the outside of the casing to shift said valve means and vary the control by the valve means of fluid passing through the transfer passage, a reversely movable actuator carried by the casing and mounted outside of the reservoir and extending thereinto and thrusting, when actuated, in one direction against the piston, and a spring for moving the piston in the opposite direction.

3. A check mechanism comprising a casing formed with a reservoir, and a plunger chamber communicating with the reservoir, a plunger movable in the chamber and having a transfer passage opening through its opposite ends, means H for controlling the flow of liquid through the passage during the movement of the plunger comprising a member separate from the plunger and removably mounted in the casing and extending into the passage and adjustable longitudinally and shaped exteriorly to progressively restrict the transfer passage through the movement of the plunger in one direction, said member being also formed with a by-pass therethrough for transferringthe liquid from one side to the other of the plunger, and a check alve in said by-pass, all whereby said member and the check valve are removable and replaceable, as a unit, from the outside of the reservoir, and means for actuating the plunger.

l. A check mechanism comprising a casing formed with a reservoir, and spaced apart plunger chambers in opposite portions of the casing, plungers movable in said chambers, the chambers and plungers being formed to provide transfer passages from one side of each of the plungers to the other side during the actuation thereof, an actuator extending between" the plungers and coacting alternately with the same to actuate each plunger in one direction independently of the other, and a spring for returning each plunger in the opposite direction, the casing being provided with internal shoulders for limiting the inward movement of the plungers toward each other, whereby said plungers are spaced apart a sufiicient distance to actuator is retrogradely moved out of engagement with one plunger toward the other plunger, 5. A check mechanism comprising a casing formed with a reservoir, and plunger chambers ment of the plungers in one provide a lost motion between the actuator and the plungers, when the from the outer sides thereof and extending into the passages and shaped exteriorly to progressively restrict said passages through the movedirection to control the flow of liquid therethrough during the movement of the plungers, said members having passages therein serving to transfer the liquid from one side of each plunger to the other, a check valve in each of the last passages, and a reversely movable actuator coacting with the plungers.

6. A check mechanism comprising a casing formed with a reservoir, and plunger chambers in opposite portions of the casing communicating with the reservoir and opening through outer walls of the casing, the casing having removable closures for the open outer ends of the chambers, plungers movable in said chambers respectively,

each plunger being provided with a transfer passage opening through its opposite ends, members carried by said closures and extending into the passages to control the flow of liquid therethrough during the movement of the plungers, said members being separate from the plungers and having passages thereinserving to transfer the liquid from one side of each plunger to the othena check valve in each of the last passages, a reversely movable actuator coacting with the plungers, the reversely movable actuator being mounted in the casing outside the reservoir and extending into the reservoir in position to thrust alternately against the inner ends of the plungers, and springs for moving the plungers in the oppositedirection, the casing being provided with shoulders for limiting the inward movement of the plungers toward each other, thereby providing a space between the plungers of greater width than the actuator, to provide a lost motion between the actuator and each plunger, when moved out of engagement with one plunger and toward and into engagement with the other.

7. A check mechanism comprising a casing formed with a reservoir, a plunger chamber communicating with the reservoir, a plunger movable in the chamber and having a transfer passage opening through its opposite ends, means for controlling the flow of liquid through the passage during the movement of the plunger comprising a throttling pin carried by the casing and separate from the plunger, the pin extending into the passage and mounted to have a self-alining shifting movement in the passage.

8. A check mechanism comprising a casing tending into the passage and mounted to have a self-alining radial shifting movement in the passage.

ERNEST DAVIS. 

